Yep, but we all know what a failure THAT was. It needs special PSUs to run, even a highend PSU could burn, or basically explode because of it. I think PCGH had a Enermax 1000W PSU go heaven because of the 295X2 and their over-the-specification 2x 8 pin cables drawing 400-600W. So, what I though was, when they do a full fledged dual GPU card again (no throttleing), they need more than just 2x 8 pin. But we will see, if they release the card someday.
And if it's indeed "Nano X2" then 2x pin would be enough. I think the latter would be the smarter choice, it's more than fast enough and a lot more efficient than a Fury X2 or 2x Fury X. 2x 175W (350) vs. 2x 275W (550) TDP. Speed only 10-30% slower (tops).
btw. the reason the Titan Z sucked, was also because it was too slow, they didn't had triple fans on it or hybrid like AMD had with the 295X2, they went for a single fan triple slot design, what basically was a big mistake as it slowed both GPUs down considerably (because the card was too hot for the GPUs to run at high clocks). And don't forget SLI scales somewhat poorly compared to Crossfire, that didn't help the card too. So, who buys a Titan Z for 3k$ when he can have a 295X2 for 1200$ (or was it 1500?), that also is faster and cooled by water? Yeah. I think BiggieShady nailed it.
The reason why Nvidia isn't doing a Titan X2 is simple: 1) Fury X CF is faster, if they go simple cooler again, because they run on max speed and the Titan X2 not. 2) Crossfire scales better than SLI. 3) they earn more money with customers buying 2x Titan X or 2x 980 Ti instead of just one card priced at 1000 or 1500-3000$ (depends if its a 980 Ti X2 or Titan X2). But basically the 1st reason is a big problem, they don't want a comparison where they lose again, like they lost to the 295X2 with their overly expensive Titan Z. 2x 980 Ti/Titan X is doing fine though.